Question

what will be the area of semicircle whose perimeter is 36 cm

Answer 1

Hey!!!!

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For a semicircle

=> Perimeter = 36m

=> πr + 2r = 36(2r = d)

=> 22r/7 + 2r = 36

=> (22r + 14r)/7 = 36

=> 36r = 36 x 7

=> r = 7cm

Area = 1/2x πr²

=> Area =1/2x 22/7 x 7 x 7

=> Area = 77 cm²

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Hope this helps ✌️

Answer 2

Here is your solution buddy!!!

$perimeter \: of \: semicircle \: = 2r + \pi \: r \\ 36 = 2r + \pi \: r \\ 36 = r(2 + \pi) \\ 36 = r(2 + \frac{22}{7} ) \\ 36 = r ( \frac{14 + 22}{7} ) \\ 36 = r( \frac{36}{7} ) \\ \frac{36 \times 7}{36} = r \\ r = 7cm \\ \\ area \: of \: semicircle \: = \frac{1}{2} \times \frac{22}{7} \times {r }^{2} \\ = \frac{1}{2} \times \frac{22}{7} \times 7 \times 7 \\ = 11 \times 7 \\ = 77 {cm}^{2}$
Hope it helps.